Metrolink officials accused the unidentified engineer of making three attempts to block the cameras' view. That engineer works for operating contractor, Connex Railroad LLC.
Metrolink says another engineer allegedly clipped a paper to a visor another camera in March. He is still operating Metrolink trains pending the outcome of an investigation.
Attorneys for the Brotherhood of Locomotive Engineers and Trainmen have argued that the cameras are creating a safety hazard, because sun visors have been reconfigured to carry the cameras.
The Associated Press and City News Service contributed to this report.